The Need for Diversity

Insects and diseases affecting trees are not new; in fact, both occur naturally and help keep trees and forests healthy. But when
invasive, non-native species are brought into the lifecycle, the results can be overwhelming.

The overplanting of ash trees in the years following Dutch elm disease (DED) contributed to our state's current situation with the
emerald ash borer. Drawing on the lessons from DED, the Nebraska Forest Service and our many partners are seeking to change that.

When we focus on replanting with tree
diversity, we continue to build on a tree planting legacy that Nebraskans will be able to enjoy for decades to
come.

Medium and Large Deciduous Trees to Replace Ash – typically over 25’ tall at maturity

Red Oak - and related species (Quercus rubra): Red oaks are less tolerant of high pH soils
and are generally more suited to eastern Nebraska; closely related species include Red Oak, Shumard Oak, Black Oak, Buckley Oak, and
Shingle Oak; most species tough and reliable with lustrous sharp-pointed leaves and beautiful fall color from russet to bright red in
fall; 40-60’x 40-60’.

American Linden - and related
species(Tilia americana): American linden is a tough and adaptable native with fragrant spring flowers favored by
bees and other pollinators; 60’x 40’. Littleleaf linden (Tilia cordata) is similar but with a more formal, pyramidal shape.
Silver linden (Tilia tomentosa) has very attractive dark-green leaves with pubescent (silvery) undersides that give them
better resistance to Japanese beetles.

Sugar Maple and related species (Acer saccharum): Sugar maple is a
beautiful and underused tree with great fall color that grows well in eastern Nebraska; common cultivars include ‘Fall Fiesta’ and
‘Legacy’; the Caddo ecotype from Oklahoma has exceptional heat and drought tolerance and includes the cultivars ‘John Pair’ and
‘Autumn Splendor’; 40-60’x 35-50’. Bigtooth Maple (Acer grandidentatum) is a related species native to Rocky Mountains that is
better suited for western Nebraska.

Pecan/Hickory (Carya spp.): Pecan and Bitternut Hickory are the most adaptable
hickories for eastern Nebraska and both deserve to planted in greater abundance; relatively upright and fast growing; transplant when
small; 50-70’x 40-60’.

American Elm(Ulmus
americana): Disease-resistant cultivars of American elm worth planting include ‘Princeton’ & ‘Jefferson’ as well local
ecotypes selected by NSA. Such elms provide high-canopy, arching shade and grow 60-80’ x 60-80’. Beware! American elms need careful
structural pruning when young and should be limited primarily to street tree and park plantings.

Elms (Ulums spp): Several hybrid elms with proven drought tolerance and
adaptability are now available including ‘Triumph’, ‘Accolade’, ‘Frontier’, and ‘New Horizon’. Japanese elm (Ulmus davidiana var.
japonica) including the ‘Discovery’ cultivar is an especially promising mid-sized tree. Beware! All elms require frequent structural
pruning when young to maintain good form.

Hackberry (Celtis occidentalis): Common native with legendary adaptability;
irregular habit when young but matures to stately rounded crown; great street tree and good for a variety of wildlife including several
butterfly species; 50-70’ x 40-60’.

Planetree/Sycamore (Platanus spp.): Sycamore is a terrific choice for the eastern
half of Nebraska; tough and tall growing with beautiful mottled and creamy/white bark; good on wet sites; up to 80’x 50’. Sycamore’s very
similar hybrid cousin the London Planetree (Platanus x acerifolia) is more commercially available and is anthracnose
resistant, but not quite as hardy.

Ginkgo (Ginkgo biloba): An ancient species dating to the age of dinosaurs;
distinctive fan-shaped leaves that turn golden-yellow in fall; upright branching habit; slow growing but tolerant of poor soils; 50’x
40’.

Black
Walnut(Juglans nigra): This tough native can be a bit messy, but is still a good tree for backyards
and parks; incredible drought tolerance and good yellow fall color; don’t plant near vegetable gardens; great for wildlife; good
lumber tree; 60’x 45’.

Red Maple (Acer rubrum): Popular tree with red fall color; prefers moist sites and not
as drought tolerant as other species; ‘Autumn Blaze’ is an overplanted, silver-maple hybrid that should be used sparingly; 40-60’x
40-60’.